Short answers, pulled from the story.
Biscuit comes from the Old French word bescuit, derived from the Latin bis (twice) and coquere (to cook), meaning literally "twice-cooked". The name reflects the original production method: biscuits were first baked, then dried out in a slow oven to remove all moisture.
In the United States and much of Canada, sweet flat biscuits are called cookies, while the American term biscuit refers to a fluffy quick bread similar to a scone. The divergence reflects a genuine parting of culinary traditions; in the United Kingdom, cookie refers narrowly to a sweeter baked dough typically containing chocolate chips or raisins.
Gingerbread was brought to Europe in 992 by the Armenian monk Gregoire de Nicopolis. He left Nicopolis Pompeii in Lesser Armenia and settled in Bondaroy, France, near Pithiviers, where he spent seven years teaching French priests and Christians how to cook gingerbread.
Royal Navy hardtack under Queen Victoria was machine-made at the Royal Clarence Victualling Yard in Gosport, Hampshire, stamped with the Queen's mark and the oven number. Dough was rolled into sheets about two yards long, stamped into roughly sixty hexagonal biscuits per sheet, and the hexagonal shape was chosen to reduce material waste and improve packing.
Huntley and Palmers invented the decorative biscuit tin in 1831. By 1900, the company's biscuits were sold in 172 countries, and the tin was a key reason British biscuits could be exported around the world.
Biscuits are divided into four categories based on process and ingredients: crackers, which are savoury with a crispy open texture; semi-sweet biscuits, which have consistent texture and colour with low sugar and fat; short dough biscuits, which have high sugar and fat and include products like digestives and shortbread; and cookies, the widest category, which have very soft doughs and high sugar and fat content.